By Matt A. Barr
Seoul, South Korea has a unique air quality problem. More often than not, a persistent haze colors its skies a dull gray and quickly crowds out the blue sky. Many highly industrialized cities experience these conditions, especially those whose economic progress developed too fast for environmental policy to keep up.
Efforts to bring emissions under control were implemented in 2005 by a Special Act of the South Korean government. In particular, PM10, NO2, and VOC emissions were targeted by the legislation with the goal of reducing them to ½ of the levels measured in 2001. This was to be accomplished by 2014, but observations and measurements of air pollution have deviated significantly from what many computer models predicted. While PM10 concentrations are down, NO2 and O3 concentrations have gone up and consistently remain above prescribed levels, despite regulatory actions taken within the past decade. The question is why?
Enter EAS atmospheric chemist Dr. Greg Huey. This summer, Dr. Huey and his team of researchers traveled to Korea to help answer this question. For six weeks, he and his group flew several missions on NASA’s DC-8 airplane, an aircraft outfitted with a 25,000-lb payload of instruments used to monitor air pollutants at a variety of altitudes. The data they gathered, along with measurements from ground stations and satellites, will be used to get a better understanding of air pollution sources in the Seoul Metropolitan Area (SMA). In doing so, their data is expected to help characterize air pollution in new ways and potentially transform how air quality is monitored and improved for decades to come.
In conjunction with KORUS-AQ and other Korean government programs established to improve SMA’s air quality, NASA is developing a series of Geosynchronous satellites that will be capable of measuring air pollution with much greater resolution than what is possible with current satellites. Right now, the orbits of satellites that monitor air quality pass over a specific region during a small window of time. This significantly limits their ability to obtain a full picture of how air pollution changes in that region. That window of time will broaden with the new generation of satellites, scheduled to be launched by 2020. The combination of data from the new satellites, ground station monitors, and in-flight observations is expected to reveal a clearer picture of Seoul’s pollution sources and perhaps answer questions about why environmental regulations have not led to the expected improvements in Seoul’s air quality.
Two undergraduates, Maddi Frank and Maddie Nisi, accompanied Dr. Huey on his trip. They worked to help calibrate and maintain the instruments, two of which were mass spectrometers designed and built by Dr. Huey’s lab. These mass spectrometers sample air during the flights and analyze it in real time to measure a series of important pollutants. Some of the discoveries made during the flights contradicted widely-held assumptions about where much of the pollution was coming from. These findings have yet to be published, and they will remain so for our post here, but the take-away is that new scientific discoveries were unfolding before everyone’s eyes. For Maddi and Maddie, that brought a certain element of excitement to what was already the trip of a lifetime.